Failure of Coaxial Cable J4 of the TCAS Top Antenna

TASK 34-43-00-810-812-A
Failure of Coaxial Cable J4 of the TCAS Top Antenna

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-43-00-740-001	BITE Test of the TCAS
ASM 344301
AMM 34-43-11-000-001	Removal of the TCAS Antenna
AMM 34-43-11-400-001	Installation of the TCAS Antenna
AMM 34-43-34-000-001	Removal of the TCAS Computer
AMM 34-43-34-400-001	Installation of the TCAS Computer

3. Fault Confirmation
Subtask 34-43-00-740-066-A

A. Test
(1) Do the BITE test of the TCAS AMM 34-43-00-740-001.

4. Fault Isolation
Subtask 34-43-00-810-154-F ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message TCAS TOP ANTENNA(7SG1)COAXIAL J4:

(1) Do a check of the resistance between:

The core and the shield of coaxial cable J4 (86600 ohms +/- 8660 ohms) ASM 344301.

(a) If the resistance value is in the specified limits:

(b) If the resistance value is out of the specified limits:
1 Remove the ANTENNA-TCAS, TOP [7SG1] AMM 34-43-11-000-001.

Disconnect coaxial cable J4 from the TCAS top antenna (7SG1).
Do a check of the connector for moisture:
- If there is moisture, dry and clean the connector.
Do a check of the resistance of the TCAS top-antenna connector (86600 ohms +/- 8660 ohms).

2 If the resistance value is in the specified limits:

3 If the resistance value is out of the specified limits:

Subtask 34-43-00-740-067-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:12 UTC